This work was developed with the purpose of studying the behavior of soybeans dimensions according to the variation of the moisture content. The research was conducted with six varieties, two transgenic and four normal, with the moisture content: 10%, 12%, 15%, and 20% b.s., and the dimensions were determined based on the method used by MILANI et al. (2000). The results indicated that the soybeans varieties showed a differentiated behavior of the dimensions length, width and thickness as a function of moisture content increases, and the normal and transgenic soybeans had different behavior.